/**
 * Subject interface
 * In this interface , we can only declare top 3 function,
 * other function we can define in an abstract class which implements
 * this interface
 */

import java.util.*;

public interface Subject {
    public abstract void attach(Observer o);

    public abstract void detach(Observer o);

    public abstract void sendNotify();

    public abstract Vector getState();

    public abstract void setState(String act, String str);
}